ABSTRACT
For example, if trainee salespeople take a test at the end of their training period, can these test scores be used to predict their first-year sales, and how accurate are these predictions? One way to answer such a question is to collect both the test scores and the first-year sales of a number of salespeople (who have already completed their first year). The next step is to draw a scatter diagram of these data. If the diagram indicates a possible linear trend, then, instead of calculating Pearson’s r, we ‘fit’ a straight line though the ‘data points’. If the equation of this line is obtained using Formulae (15.1) and (15.2) this line is called the regression line, and the equation of the line is called the linear regression equation.
